Syringe

Abstract

A needleless syringe for injecting an injection objective substance into an injection target area of a living body is provided. The syringe includes an enclosing unit enclosing the injection objective substance, and an ignition device including an ignition charge and flowing an ignition current so that the ignition charge is combusted. The syringe also includes a pressurizing unit pressurizing the injection objective substance, and a flow passage unit defining a flow passage so that the pressurized injection objective substance is allowed to inject to the injection target area. The pressurizing unit raises a pressure applied to the injection objective substance to a peak pressure for the injection objective substance to penetrate through a surface of the injection target area and then lowers the pressure applied to the injection objective substance to a waiting pressure within 2 msec after the ignition current was allowed to flow to the ignition device.

What is claimed is: 
     
       1. A syringe for injecting an injection objective substance into an injection target area of a living body without using any injection needle, the syringe comprising:
 an enclosing unit which encloses the injection objective substance; 
 an ignition device which includes an ignition charge and flows an ignition current so that the ignition charge is combusted; 
 a pressurizing unit which pressurizes the injection objective substance enclosed in the enclosing unit; and 
 a flow passage unit which defines a flow passage so that the injection objective substance, which is pressurized by the pressurizing unit, is allowed to inject to the injection target area, 
 wherein the pressurizing unit raises a pressure applied to the injection objective substance to a peak pressure for the injection objective substance to penetrate through a surface of the injection target area and then lowers the pressure applied to the injection objective substance to a waiting pressure within 2 msec after the ignition current was allowed to flow to the ignition device. 
 
     
     
       2. The syringe according to  claim 1 , wherein the pressurizing unit raises the pressure applied to the injection objective substance to the peak pressure and then lowers the pressure applied to the injection objective substance to the waiting pressure within 1.7 msec after the ignition current was allowed to flow to the ignition device. 
     
     
       3. The syringe according to  claim 1 , wherein the waiting pressure is not more than 50% of the peak pressure. 
     
     
       4. The syringe according to  claim 1 , wherein the ignition charge is any one of explosive charges of an explosive charge containing zirconium and potassium perchlorate, an explosive charge containing titanium hydride and potassium perchlorate, an explosive charge containing titanium and potassium perchlorate, an explosive charge containing aluminum and potassium perchlorate, an explosive charge containing aluminum and bismuth oxide, an explosive charge containing aluminum and molybdenum oxide, an explosive charge containing aluminum and copper oxide, and an explosive charge containing aluminum and iron oxide, or an explosive charge composed of a combination of a plurality of the foregoing explosive charges.